LICHENS AND LICHEN. PARASITES

DODGE-LICHENS A ~ LICHEN D PARASITES 101
.\l,c,tl~rci;~ 0-4-0.7 mm. in diameter, immersecl in the thallus when young, becoming elevated
(.ol~stt-ictccl at the base when mature; disc black, plane to convex, margin concolorous, not elev;ltccl;
l)arathecium about SOp thick, consisting of a fastigiate cortex 30p thiclr, of very slender,
conglrttiii;~te black hyphae at right angles to the surface and a loosely woven subhyaline medulla
tllic*lr, solrlc\vhat thicker in old apothecia, hyphae 3p in diameter ; hypothecium 150-180r thick,
tllillliit~g to~vard thc margin, dark-brom, pseucloparenchymato~~s, cells thin-walled, nearly spherial)o~~t
4-,5p ill diameter; thecium 50r tall ; paraphyses slender, repeatedly dichotomous above
tllr ;lsc.i, (*~~ttiilg otf spherical, thick-walled black cells about 4p in diameter, imbedded ill tile epitIlc,c*i;~I
gel; i~sci 25 X 8-gP, clavate to subcylilldric with thick wall and tip when young, becoining
bt.()ittlly c1lil)soidal with a long stipe, 8-spored; ascospores unicellular, hyaline, ellipsoidal, about
8 X 44.
1iill.g George V Land: Aurora Peak, 1,860 ft., A. L. McLean, A.A.E. 91.
LECIDEA HARRISSONI Dodge, sp. nov.
Type: Quceii Mary Land: Possession K~uiatak, 66" 45' S., 98" 30' E., C. T. Harrisson,
A.A.E. 53.
Areol;~e pttrvae, sparsae, 0.3 mm. diametro, albae, laeves, marginibus laevibus; cortex fastigiatlls,
psrl~tlopal~enchymaticus. Apothecia nigra, immarginata, 0.2 mm. diametro; parathecium
illdistill(.tulll ; hypothecium 2OP crassitudine, hy phis conglutinatis dense contextum, cellulis isodiillllot~.ic*is,
Sp diametro; thecium 35r altitudine; paraphyses 1-2-dichotomae, apicibus tenuibus
cl~vatis, ~uia c~un cellulis sphaericis pachydermeis, fuligineis, circiter 4r diametro; asci clavati,
:id 20 x 10-llr, stipite circ. lop longitudine, apice incrassata ; ascosporae octonae, hyalinae, longe
ellipsoideac, apicibus snbacutis, pachydermene, 7-8 X 34p.
Tll;~ll~w of small, scattered areoles, 0.3 mm. in diameter, white, smooth, margin smooth; cortex
fastipiiite, pseltdopareiirhymatous. Apothecia black, immarginate, 0.2 mm. in diameter, paratlle(*i~~ni
not differentiated (perhaps represented by a narrow, blackened structure similar to the
thallille cortex at the base of the apothecium), medulla of very loosely woven, more or less vertical
llypI1~e ; liypothecium 20Cr thick, of densely woven conglutinatc hyphae with nearly isodiametric
cells, abont 3r in diameter i thecium 35r tall ; psraphyses once or twice dichotomous above the asci,
slellder, tips clavate, cutting off spherical thick-walled dark fuliginous cells, about 4r in diameter;
nsci c.lavate, beroming broadly so, about 22 X 10-11p with a stipe about lop long, tip thickened,
protoplast rounded; asreospores hyaline, long ellipsoid with somewhat pointed ends, wall rather
thiclr, 5-8 X 34p.
Onr illaterial is very scanty. Apparently tlie asci mature near the sides first, with new asci
forlllillg to\vttrd the centre, leaving the exhausted thecium to darken so much it might be taken
for the parathecium as the disc becomes increasingly elevated and conv~x. The small interstices
between the med~illary hyphae entrap much air, so that if care is not taken to remove it,
it lllay be luistaken for a carbonaceous layer below the hypothecium, but when the hyphae are
fillally thoroughly wettcd in the mounting medium, the smaller branches of the medullary hyphae
are well to pass directly into the hypothecium.
Queen Mary Land : Possession Nunatak, 66" 45' S., 98" 30' E., C. T. Harrisson, A.A.E. 53.
MYKOBLASTUS Norm.
Nykoblasltis Norm., Nyt Mag. Naturvidensk., 7, 24; 1853.
Locidecc sect. M~coblastus Th. Fr., Lich. Scand., 1, 479; 1874.
-$fega,!ospo,*n Mass., Riccrch. Autonom. Lich. Crost. 105 ; 1852 non Mey. & Fw., 1843.
Oeden~ocarpzcs Trev., Linnaea, 28, 289 ; 1856.